[PATCH] drm/amdgpu: Skip init fbdev if virtual_display is enabled

[Alex Deucher]

On Fri, May 20, 2022 at 10:49 AM Slivka, Danijel <Danijel.Slivka at amd.com> wrote:
>
> [AMD Official Use Only - General]
>
> But for virtual display enabled we are not using display capability so shouldn't it be considered as hw without DCE.

I thought the goal of virtual DCE was for it to be just like real DCE.
Why would you want to treat it differently?  There is no need to
register an fbdev device if there is no display hardware, virtual or
real, but I don't see why you would want to treat virtual DCE any
differently than real DCE.

Alex

>
> BR,
> Danijel Slivka
>
> -----Original Message-----
> From: Alex Deucher <alexdeucher at gmail.com>
> Sent: Friday, May 20, 2022 4:33 PM
> To: Slivka, Danijel <Danijel.Slivka at amd.com>
> Cc: amd-gfx list <amd-gfx at lists.freedesktop.org>
> Subject: Re: [PATCH] drm/amdgpu: Skip init fbdev if virtual_display is enabled
>
> On Fri, May 20, 2022 at 10:12 AM Slivka, Danijel <Danijel.Slivka at amd.com> wrote:
> >
> > [AMD Official Use Only - General]
> >
> > Hi,
> >
> > Based on the code we shouldn't init the fbdev on hw without DCE:
>
> That comment means don't init fbdev on chips without display hardware (either real or virtual).  E.g., iceland or MI100.
>
> Alex
>
> >
> >         /*
> >          * 1. don't init fbdev on hw without DCE
> >          * 2. don't init fbdev if there are no connectors
> >          */
> >         if (adev->mode_info.mode_config_initialized &&
> >             !list_empty(&adev_to_drm(adev)->mode_config.connector_list)) {
> >                 /* select 8 bpp console on low vram cards */
> >                 if (adev->gmc.real_vram_size <= (32*1024*1024))
> >                         drm_fbdev_generic_setup(adev_to_drm(adev), 8);
> >                 else
> >                         drm_fbdev_generic_setup(adev_to_drm(adev), 32);
> >         }
> >
> > For virtualization we always use virtual_display and doesn’t have the hw DCE for that reason setting up fbdev should be skipped.
> >
> >
> > BR,
> > Danijel Slivka
> >
> > -----Original Message-----
> > From: Alex Deucher <alexdeucher at gmail.com>
> > Sent: Friday, May 20, 2022 3:30 PM
> > To: Slivka, Danijel <Danijel.Slivka at amd.com>
> > Cc: amd-gfx list <amd-gfx at lists.freedesktop.org>
> > Subject: Re: [PATCH] drm/amdgpu: Skip init fbdev if virtual_display is
> > enabled
> >
> > On Fri, May 20, 2022 at 3:59 AM Danijel Slivka <danijel.slivka at amd.com> wrote:
> > >
> > > In case virtaul_display is enabled there is no hw DCE so need to
> > > skip setting up fbdev.
> >
> > Wouldn't you theoretically still want fbdev even if it is virtual?
> >
> > Alex
> >
> > >
> > > Signed-off-by: Danijel Slivka <danijel.slivka at amd.com>
> > > ---
> > >  drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 1 +
> > >  1 file changed, 1 insertion(+)
> > >
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > > b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > > index 3b9dc1803be9..8d03eec49eef 100644
> > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > > @@ -2095,6 +2095,7 @@ static int amdgpu_pci_probe(struct pci_dev *pdev,
> > >          * 2. don't init fbdev if there are no connectors
> > >          */
> > >         if (adev->mode_info.mode_config_initialized &&
> > > +           !adev->enable_virtual_display &&
> > >             !list_empty(&adev_to_drm(adev)->mode_config.connector_list)) {
> > >                 /* select 8 bpp console on low vram cards */
> > >                 if (adev->gmc.real_vram_size <= (32*1024*1024))
> > > --
> > > 2.25.1
> > >